PROBLEM TO BE SOLVED: To provided a sheet discharge device for reliably pushing sheets out of a pair of discharge rollers without damaging the sheets and damaging images on the sheets, and to provide an image forming device equipped therewith and a post-processing device.SOLUTION: A sheet discharge device includes a pair of discharge rollers 20 having a first roller 21 and a second roller 22 pressure-contacting each other for discharging sheets from a pressure-contact part N. The first roller 21 has a protruded portion 41 formed which is protruded in a roller radial direction for pushing the rear ends of the sheets to be discharged along with the rotation of the first roller 21. The protruded portion 41 is provided on a flange part 45 a predetermined distance apart from a peripheral end 43a of a cylinder part 42 of the first roller 21. The distance from the rotational center of the flange part 45 to a front end 41c in the radial direction of the protruded portion 41 is made equal to or shorter than the radius of the cylinder part 42.